The Obama administration is preparing to draw a red line against coal pollution, with a proposal that for the first time would limit climate-changing emissions from all future power plants.

The Environmental Protection Agency’s proposed rule, set to come out Friday morning, fulfills a key promise to President Barack Obama’s environmental base — while offering a potent line of attack for Republicans in 2014. It kicks off a major effort by Obama’s agencies to tackle climate change without waiting for help from Congress.

The White House-vetted proposal would impose strict pollution standards requiring future coal-burning plants to capture and store at least 40 percent their carbon emissions, according to information provided to POLITICO late Thursday.

Obama’s critics say the emerging technology is too expensive and amounts to a ban on building coal plants. The administration argues it has invested unprecedented amounts of money in advanced coal technology, and it’s time for the industry to step up and cut down greenhouse gas pollution.

The rule is the first of two major climate regulations that EPA has in the works. A second, more sweeping draft rule due in June will take aim at carbon pollution from the nation’s thousands of existing power plants — the largest source of U.S. greenhouse gas emissions.

Obama ordered the EPA to take the steps in his climate policy speech at Georgetown University this summer, saying that “I refuse to condemn your generation and future generations to a planet that’s beyond fixing.” But the agency has been headed in this direction ever since it established its first greenhouse gas regulations in 2009, including tightening fuel economy standards on cars. In 2010, EPA agreed to tackle power plants after settling a lawsuit by environmentalists.

The administration hopes the rules will bolster the United States’ credibility in global climate talks that are aimed at crafting a treaty by 2015.

In her speech announcing the rule Friday morning, EPA Administrator Gina McCarthy will call Obama’s Georgetown speech “one of the most important speeches of his Presidency,” according to excerpts of the speech obtained by POLITICO.

“Less than three months ago, President Obama stood outside in sweltering heat to unveil a new national plan to confront the growing threat of climate change,” McCarthy will say, announcing that the agency is now “taking one of those important steps, with a proposal to limit carbon pollution from new power plants.”

“Power plants are the single largest sources of carbon pollution,” McCarthy’s speech says. “New power plants – both natural gas and coal-fired – can minimize their carbon emissions by taking advantage of modern technologies. These technologies offer them a clear pathway forward today and in the long term.”

Environmental groups have long been pushing Obama to take this kind of action, while Republican lawmakers and coal industry supporters have warned it would boost both energy prices and unemployment.

“The President is leading a war on coal and what that really means for Kentucky families is a war on jobs,” Senate Minority Leader Mitch McConnell (R-Ky.) said in a statement late Thursday, as details of the proposal began to leak out. “And the announcement by the EPA is another back door attempt by President Obama to fulfill his long-term commitment to shut down our nation’s coal mines.”

Just about everyone acknowledged that the rule’s fate will be decided in court — industry-backed lawsuits are inevitable.

“These limits on carbon pollution are so common sense that most Americans assume they’re already in place,” said League of Conservation Voters President Gene Karpinski. “Carbon pollution is already increasing rates of asthma attacks and extreme weather like floods, heat waves, and droughts nationwide. Any attempts by Congress to block implementation of these limits would go against the majority of Americans who support these common sense steps and would only benefit the country’s biggest polluters.”

Opponents argue that the standards are unachievable, carbon capture is too expensive and the technology isn’t adequate to meet Clean Air Act requirements. Setting such tight standards will “destroy, not encourage, the development” of new carbon capture projects, said Mike Duncan, CEO of the American Coalition for Clean Coal Electricity.

While it won’t affect existing plants, EPA’s proposal would put the squeeze on coal: Any coal-burning power plant built in the future would be limited to 1,100 pounds per megawatt hour of CO2 emissions, according to McCarthy’s planned speech. That means a state-of-the-art coal plant would have to employ expensive and thus-far uncommonly used technologies to capture around 40 percent of its carbon emissions.

Obama’s critics say it would make building any coal plant a non-option. With scores of older coal plants expected to close in the next several years, that would be yet another hit to a coal mining industry that is hemorrhaging jobs in states like West Virginia, Ohio, Kentucky and Indiana.The rule is already a political talking point for 2014 races in coal-heavy states like Kentucky and West Virginia.

The rule also imposes separate, slightly tighter carbon limit on new power plants fueled by natural gas. But those plants aren’t expected to have trouble meeting it – the standard is set to match a top-flight natural gas plant’s carbon output. Large natural gas plants would be capped at 1,000 pounds per megawatt hour of CO2. Smaller natural gas plants get a little more leeway, with an 1,100 pounds per megawatt hour limit.

The rule wouldn’t affect nuclear plants or wind or solar power, which produce no greenhouse gases.

By law, the proposal is due to be finished in a year, after which industry groups are certain to challenge the standards in court.

The new rule is a second swing for the EPA. It’s a rewrite of an initial draft the agency put out in March 2012, which appeared more vulnerable to court challenges.

But the idea behind the new proposal remains the same: No longer will coal-fired power plants be free to be the greenhouse gas giant of the energy world.

Though it will take a year to finalize the rule, under the Clean Air Act’s requirements it will have an immediate effect on the construction of any new power plants.

EPA’s 2012 proposal listed 15 planned coal plants already holding air permits that might be allowed dispensation from the rule. At least six of those projects have since been canceled, three switched to natural gas projects, and several more are unlikely to come to fruition. Ten of the 15 proposed plants either included carbon capture or were to be built in such a way that the technology could be added later.

The sharp fall-off in active projects may bolster EPA”s argument that nobody is really planning on any new coal-fired power plants without carbon capture in the near future, particularly given the nation’s natural gas boom.

But Republicans are spreading the message that coal isn’t the EPA’s only target.

“A War on Coal is only the first phase of the radical left’s plan,” the National Republican Senatorial Committee said in an email blast Wednesday, warning that a “war on oil” will follow. “The dirty little secret is that they want electricity costs to skyrocket.”

The NRSC said consumers and workers will feel the pinch in “states like Alaska, Kentucky, West Virginia, Louisiana, Michigan, North Carolina, Michigan and Iowa” — not coincidentally, all crucial states in the 2014 Senate electoral calendar.

Some coal-state Democrats will also be unhappy with EPA’s efforts, especially in West Virginia, where Democratic Sen. Joe Manchin complained this week that his state is “having the living crap beat out of us by this administration.”

The EPA proposal could create electoral discomfort for Democrats facing voters this year, like Virginia gubernatorial candidate Terry McAuliffe, as well as in 2014.

EPA argues that the coal industry is shifting blame, as the industry faces mounting competition from low natural gas prices and improvements in wind and solar, and as costs mount for aged power plants kept open well past their economic prime.

“I take the administration at their word when they say they’re not motivated by a war on coal,” said Paul Bledsoe, a former official on a Clinton White House climate change task force. “What they’re motivated by is an effort to reduce emissions across the U.S., specifically in the power sector, in the cheapest way, but also in a way that can help generate new technologies that can have broad applicability.”

He questioned, however, whether regulations alone would be enough to advance carbon capture in the marketplace.

Those who support the rule say it’s long overdue for the U.S. to take serious action on global warming, noting that it’s been three years since cap and trade died in the Senate. And scientists say time is rapidly running out for the world to head off the worst damage from rising seas, worsening storms and droughts and spreading disease.

“The evidence is overwhelming, the science is clear, and the threat from climate change is real and urgent. This is my judgment and it is the almost universal judgment of the scientific community,” Energy Secretary Ernest Moniz, a physicist, testified before Congress on Wednesday.

A warming planet threatens “our way of life,” Moniz said.

“Rising sea levels and increasingly severe droughts, heat waves, wildfires, and major storms are already costing our economy billions of dollars a year and these impacts are only going to grow more severe. Common sense demands that we take action,” he said. “This is the driving force behind the President’s Climate Action Plan.”

For all the drama, the big prize for climate activists is the EPA rule on existing power plants that the agency is due to propose next June.

Scaling back emissions from all of those plants would be costly for utilities, especially those that own high-carbon coal-fired power plants.

The agency is only beginning the rule-writing process for existing plants, and with plans to employ a never-before-used portion of the Clean Air Act, there’s scant agreement on exactly what the rules will look like. But generally, EPA is expected to adopt guidelines for cutting carbon that states will then have to decide how to meet.

States could take steps like creating carbon-credit trading systems, shifting power production to less polluting sources such as natural gas or wind, or finding ways to cut back on demand for power from households and businesses.